Research Articles published by Science Publishing GroupWater reuse is one of the alternatives to counteract the already experienced water shortages. However water reuse as any other investment is associated with costs. This article looks at water reuse for irrigation as one of the areas that has recently gained attention. However, water reuse requires a prior installation of wastewater treatment and the irrigation systems of which all requires financial resources. Analysis of the costs and benefits of water reuse remains one of the key tools for decision making. Unfortunately there has been no universal way for doing cost benefit analysis that can fit all reuse applications and the local settings. The objective of this study was to customize the existing water reuse cost benefit analysis methods and develop cost benefit analysis for water reuse in irrigation. The net benefit value approach was studied, examined and modified to incorporate all the relevant cost items and benefits associated with water reuse in irrigation. Based on the approach developed a discussion have been made whereby it was evident that the main cost elements for water reuse in irrigation are those associated with land for installations, the treatment plant and the irrigation systems involving their installations, operation and maintenance. On the other hand it has been shown that the main elements for benefits are related to natural resources recovered, improved agricultural production and the environmental benefits.